Organic matter
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 | It has been suggested that natural organic matter be merged into this article. (Discuss) Proposed since July 2008. |
| It has been suggested that sedimentary organic matter be merged into this article. (Discuss) Proposed since July 2008. |
Organic matter (or organic material) is matter that has come from a once-living organism; is capable of decay, or the product of decay; or is composed of organic compounds. The definition of organic matter varies upon the subject for which it is being used.
Soil organic matter
The organic matter in soil derives from plants and animals. In a forest, for example, leaf litter and woody material falls to the forest floor. This is sometimes referred to as organic material.[1] When it decays to the point in which it is no longer recognizable it is called soil organic matter. When the organic matter has broken down into a stable substances that resist further decomposition it is called humus. Thus soil organic matter comprises all of the organic matter in the soil exclusive of the material that has not decayed.[2]
One of the advantages of humus is that it is able to withhold water and nutrients, therefore giving plants the capacity for growth. Another advantage of humus is that it helps the soil to stick together which allows nematodes, or microscopic bacteria, to easily decay the nutrients in the soil.[3]
There are several ways to quickly increase the amount of humus. Combining compost, plant or animal materials/waste, or green manure with soil will increase the amount of humus in the soil.
- Compost: Decomposed organic material.
- Plant and animal material and waste: Dead plants or plant waste such as leaves or bush and tree trimmings, or animal manure.
- Green manure: Plants or plant material that is grown for the sole purpose of being incorporated with soil.
These three materials supply nematodes and bacteria with nutrients for them to thrive and produce more humus, which will give plants enough nutrients to survive and grow.[3]
Decay
Organic matter may be defined as material that is capable of decay, or the product of decay (humus), or both. Usually the matter will be the remains of recently living organisms, and may also include still-living organisms. Polymers and plastics, although they may be organic compounds, are usually not considered organic material, due to their poor ability to decompose. A clam's shell, while biotic, would not be considered organic matter by this definition because of its inability to decay.
Measurements of organic matter generally measure only organic compounds or carbon, and so are only an approximation of the level of once-living or decomposed matter. Some definitions of organic matter likewise only consider "organic matter" to refer to only the carbon content, or organic compounds, and do not consider the origins or decomposition of the matter. In this sense, not all organic compounds are created by living organisms, and living organisms do not only leave behind organic material. A clam's shell, for example, while biotic, does not contain much organic carbon, so may not be considered organic matter in this sense. Conversely, urea is one of many organic compounds that can be synthesized without any biological activity.
Vitalism
The equation of "organic" with living organisms comes from the now-abandoned idea of vitalism that attributed a special force to life that alone could create organic substances. This idea was first questioned after the abiotic synthesis of urea by Friedrich Wöhler in 1828.
See also
- Biofact (biology)
- Biomass
- Detritus
- Humus
- Natural organic matter
- Organic geochemistry
- Total organic carbon
Compare with:
References
- ^ http://www.epa.gov/epaoswer/non-hw/organics/index.htm
- ^ http://soils.usda.gov/sqi/concepts/glossary.html
- ^ a b Crow, W. T. “Organic Matter, Green Manures and Cover Crops For Nematode Management.” University of Florida. The Institute of Food and Agricultural Sciences Feb. 2009 Web 10 Oct. 2009